The door is made with a triple-lite insulated glass unit and a frame of aluminum rails. The insulated glass unit has a stepped cross-section with the outer glass lite being larger than the inner glass lites. An opaque non-conductive ceramic frit forms a rectangularly shaped border to mask the mounting of the inner glass lite(s). An electrically conductive coating on the outer glass lite is insulated from the aluminum rails of the frame by a plastic strip disposed between the outer glass lite and each rail.